Dear Rav Halberstadt, Thank you for the eye opening information on the canned salmon. Can you please clarify the following point. Does it matter or not whether the worms/bugs are microscopic or see able to the human eye? What is the case with the worms/bugs in the canned salmon. I heard from 2 Rabbis that in the case of lettuce that is the human eye can see them, no matter how small they are, then the lettuce must be cleaned before eating, but that if the worms/bugs are microscopic, then there is no issur in eating the lettuce. Thank you for the clarification.

All Poskim agree that creatures that are not visible to the human eye, such as microscopic creatures, are not forbidden to be eaten according to the Torah. The Aruch Hashulchan and Igrot Moshe explain: the air is filled with tiny creatures [germs], and in every breath a person swallows several thousands or maybe millions of them. Inevitably they are not included in the vermin and insects that the Torah prohibited. [ערוך השולחן סימן פד סעיף לו, אגרות משה יו"ד ח"ב סימן קמו ואבה"ע ח"ג סימן לג, שש"כ פרק ג סעיף לז הערה קה, ספר בדיקת המזון כהלכה של הרב משה ויא חלק ראשון בקונטרס מבוא פרק ד סעיף 2 ובחלק ההלכות פרק ב סעיף ב, ושם בהערות מפורטים מקורות רבים נוספים]. Canned Salmon; according to Rabbi Revach’s Machon and the Rabbis supporting them, it should not be eaten if it is from the USA or China because of the problem of Anisakis worms. If it is from Norway or Chile there is most probably no problem with the external “Salmon lice” because the skin is removed before it is canned. It is recommended to buy it with a good Hechsher to be sure no Lice found its way to the cans. Rabbi Vaye disagrees; he told me that one can buy canned salmon from the USA or China that is under a good Hashgachah which makes sure to clean the intestines well from all the worms. Anisakis worms are not microscopic creatures; they measure approximately 1 to 4 centimeters, and are clearly visible. According to Shulchan Aruch Yoreh De’ah 84, 16. Worms that grow in the flesh of the fish are permitted, but if they come from the outside they are forbidden. And this indeed is one of the main points of disagreement between Rabbi Revach and Rabbi Vaye. According to the scientists it is clear that the fish swallow the Anisakis worms from the outside. However according to Rabbi Revach they are swallowed when they are already a size that is visible to the human eye, therefore they are forbidden. According to Rabbi Vaye they are swallowed while they are a microscopic size, therefore it is considered that they grew in the flesh of the fish, and are permitted. In any case it is highly recommended to buy fish under a good Hashgachah that is familiar with the worms and sea lice issues or consult Kashrut experts in every specific case, because things change from time to time and place to place.